In a Japanese Patent Application Publication No. 2011-020652, there is described a conventional technology related to a spare tire carrier of an automobile. In such spare tire carrier 100, as shown in FIG. 9, a main body portion 101 placing a spare tire T is connected to a frame material 100f forming a floor portion of a vehicle body by a hinge 103 at a front end so as to lift up a rear portion thereof or unload on a road surface. The main body portion 101 can be held by being suspended under a floor plate 100b of the automobile by a structure in which a suspension bolt 105 and a hook 106 are combined.
The suspension bolt 105 includes a hexagonal head portion 105h and a shaft portion 105j in which a male screw is formed. In the suspension bolt 105, in a state wherein the head portion 105h remains on the floor plate, the shaft portion 105j passes through a through hole of the floor plate 100b of the automobile. In the hook 106, there is provided a cylindrical portion 106t including a female screw on an upper portion. The female screw is screwed into the male screw of the shaft portion 105j of the suspension bolt 105. When a back end portion of the main body portion 101 of the carrier is hooked onto the hook 106, the hook 106 comes to an unrotatable state. Therefore, by rotating the suspension bolt 105, the male screw is screwed into the female screw of the hook 106 so as to raise the hook 106.